Soak Urad Daal for 1.5 to 2 hours. I soaked for 1 hour as I grinded in a wet grinder. If in mixer, you have to soak for 2 to 3 hours.

Then grind it along with green chilli and ginger into a very thick batter adding not more than 1/2 glass water.

Finely chop onion, coriander and curry leaves and mix it with this batter along with required amount of salt 1/2 tsp.

Now, heat the oil in a heavy bottom deep wok or kadai. Check the temperature by placing your hand on the wok, while keeping the flame in medium...if you can feel the heat, then drop the vadas 1 by 1.

The technique to drop vadas is to wet your right hand...take a handful of batter, and then using your water-wet thumb, make a small hole in the middle and drop the vadas instantly. The hear of oil should be that, when you drop, it should go down and instantly come up again

You can fry till golden crisp...on both sides. And then drain oil and place them in a paper towel.